In a principal aspect the present invention relates to a combustion gas detection system for use in detecting undesired combustion gases in the coolant of the cooling system for an internal combustion engine.
When servicing an internal combustion engine of a motor vehicle, a mechanic or vehicle service technician often finds that it is appropriate or desirable to investigate whether the exhaust system is leaking combustion gases into the coolant of the cooling system. For example, a crack in the vehicle engine block may result in the transmission of combustion gases into the coolant liquid of the engine cooling system. Obviously, such a condition is very undesirable and indicates a necessity for potential repair or replacement of the engine block, engine head, or other potential sources of combustion gas leakage into the cooling system.
Heretofore, a method and apparatus for detection of such combustion gases involved suction of gases from the radiator outlet of an engine cooling system by squeezing a bulb to withdraw the gases through a container of gas sensitive fluid. The mechanic or technician would rapidly pump on the rubber bulb in order to withdraw the gases through the fluid. The fluid, being sensitive to the combustion gases, would reveal the presence of combustion gases by a change of color, for example.
While such a system has proven to be useful in detecting gases, there has remained a need for an improved apparatus and method for investigating the presence of combustion gases in the coolant fluid of a cooling system for an internal combustion engine.
Briefly, the present invention comprises a combustion gas detection system which includes a transparent or translucent tube filled with combustion gas sensitive fluid. The tube includes an inlet fitting at one end which is adapted to engage and seal with the radiator cap opening of a vehicle cooling system. A check valve in a passage through the fitting leading from the radiator cap opening into the tube prevents backflow of fluid from the tube and permits inflow of gas from the cooling system. An outlet fitting for the fluid containing tube includes a flexible suction hose or conduit adapted to engage with a vacuum port of the vehicle engine. By engaging the engine vacuum port, the flexible conduit enables suction of fluid or gas from the cooling system through the transparent tube and the fluid in the tube.
When testing for combustion gas utilizing the device of the invention, the technician will start the internal combustion engine and permit it to warm to normal operating temperature. Some of the coolant fluid is removed from the cooling system so that there is a region of gas above the fluid level within the radiator. The inlet fitting of the fluid filled transparent tube is then engaged over the radiator cap opening, and an engine vacuum port leading from the tube is engaged or connected with the suction hose from the transparent tube to thereby draw gas from the cooling system through the transparent tube. The gas sensitive fluid within the detection device transparent tube typically will change color as combustion or exhaust gases react therewith to alter the pH of the fluid. By way of example, the fluid within the detection device transparent tube may be a mixture of bromothymol blue, sodium monocarbonate and water. The presence of excess carbon dioxide and/or carbon monoxide will cause such a solution to alter color from a blue color to a yellow hue.
When attempting to troubleshoot the operation of an internal combustion engine by locating the cylinder or cylinders wherein the source of combustion gas leakage occurs, removal of the ignition spark associated with each cylinder may be effected. By removing the ignition mechanism associated with one or more cylinders, a mechanic will remove that cylinder or cylinders as an exhaust gas source and by process of elimination will be able to identify whether a particular cylinder is the source of the undesired combustion gas.
Thus, it is an object of the invention to provide an improved combustion gas detection apparatus or system and method for use with internal combustion engines.
A further object of the invention is to provide a combustion gas detection apparatus which is easy to use, foolproof, rugged and economical.
These and other objects, advantages and features of the invention will be set forth in a detailed description which follows.